Optoelectronic devices have continued to gain popularity with today's top manufacturers. Specifically, microelectromechanical devices, such as actuators, motors, sensors, and microelectromechanical systems (MEMS), such as spatial light modulators (SLMs), are some of the few types of optoelectronic devices gaining in use. Such packaged SLMs and other types of MEMS devices are employable in digital micromirror device (DMD) technology, of the type designed and used by Texas Instruments of Dallas, Tex. DMD technology, or similar technology, is then employed in optical communication systems for the transmission of data via optical signals.
DMD MEMS assemblies include arrays of electronically addressable mirror elements (or “pixels”), which are selectively movable or deflectable. The mirror elements are individually movable in response to electrostatic forces from an integrated addressing circuit formed in a semiconductor substrate beneath the mirror elements. Such MEMS assemblies may be used to modulate incident light in a spatial pattern or to otherwise modulate the incident light or components thereof in phase, intensity, polarization or direction.
In wavelength division multiplexing (WDM) and dense wavelength division multiplexing (DWDM) applications, dynamic gain equalizers (DGEs) are typically employed to equalize and condition each carrier wavelength or channel in an optical signal for data to be transmitted reliably. In WDM, DWDM, DGE, and many other optical telecommunications applications, as well as in other non-telecommunications contexts, the incoming optical signal may be dispersed into multiple optical wavelength components. A typical way to disperse the wavelengths is through a diffraction grating along a single axis. After diffraction, the multiple wavelengths will continue to disperse along the dispersive axis until a lens or other optical component is used to control the dispersion. The now-separated wavelengths will then form multiple gaussian spots across the surface of the DMD or other SLM used to re-establish substantially parallel or re-converging paths for the multiple wavelengths. Groups of pixels may then be turned on or off to separately modulate the wavelength signals. However, in many systems, many available mirrors are not employed, since the incoming signal cannot reach them, resulting in lost overall resolution. In addition, the tendency of the mirror array in the SLM to behave like a grating may result in signal loss through a decrease in coupling efficiency of modulated output signals from the SLM.